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Journal of Chromatography

W D Figg, H J Yeh, A Thibault, J M Pluda, F Itoh, R Yarchoan, M R Cooper
This paper describes a reversed-phase, high-performance liquid chromatographic (HPLC) method for the isolation, detection, and quantification of TNP-470 (I) and one of its active metabolites, AGM-1883 (II), from plasma. These compounds are initially extracted from plasma with an organic solvent and then separated from one another on a C18 column. Those fractions eluting from the C18 column and containing either I or II are then derivatized through their epoxide moieties with sodium 8-quinolinethiolate (SQT)...
February 11, 1994: Journal of Chromatography
T A Willey, G F Duncan, L K Tay, K A Pittman, R H Farmen
A sensitive, quantitative reversed-phase high-performance liquid chromatographic method has been established for the simultaneous determination of butorphanol, a synthetic opioid, and its metabolites, hydroxybutorphanol and norbutorphanol, in human urine samples. The method involved extraction of butorphanol, hydroxybutorphanol, and norbutorphanol from urine (1.0 ml), buffered with 0.1 ml of 1.0 M ammonium acetate (pH 6.0), onto 1-ml Cyano Bond Elut columns. The eluent was evaporated under nitrogen and low heat, and reconstituted with the HPLC mobile phase, acetonitrile-methanol-water (20:10:70, v/v/v), containing 10 mM ammonium acetate and 10 mM TMAH (pH 5...
February 11, 1994: Journal of Chromatography
G Johansson, B Olde, M Joelsson
Ligands with an apparent affinity for various structural elements on the surface of synaptic membrane fragments have been bound to the polymers poly(ethylene glycol) and dextran. The ligand-polymer derivatives have been included in aqueous two-phase systems composed of water, poly(ethylene glycol) and dextran. The uneven distribution of the polymers resulted in the concentration of the polymer-bound ligand in one of the two phases. The effect of the ligand-polymer on the partition of membranes was studied by using synaptic membranes from calf brain, obtained by standard centrifugation methods...
February 11, 1994: Journal of Chromatography
O van Tellingen, E M Pels, R E Henrar, L J Schaaf, G E Padbury, J H Beijnen, W J Nooijen
Carzelesin (U80,244, I) is a cyclopropylpyrroloindole prodrug analog. The compound exerts its cytotoxic activity after conversion, via U-76,073 (II) to U-76,074 (III) by binding to the DNA minor groove in a sequence selective fashion. In pre-clinical investigations the drug displayed a broad spectrum activity against human xenografts in mice. To enable pharmacokinetic monitoring during the phase I clinical trials, we have developed a selective and sensitive assay for the parent compound and its two metabolites...
January 14, 1994: Journal of Chromatography
E B Asafu-Adjaye, S Y Su, G K Shiu
An automated technique involving switching valves and a filter assembly has been developed and evaluated for the on-line precipitation of proteins and peptides from plasma samples. In the set-up, the proteins were precipitated on-line by injecting the plasma sample into a stream of organic precipitating agent. The precipitates so formed are filtered on-line by a set of filter assemblies consisting of ordinary in-line HPLC solvent filters. Evaluation of the technique was performed using ibuprofen and a mixture of three estrogens, estradiol, equilin and estrone, spiked in dog plasma...
January 14, 1994: Journal of Chromatography
K C Chan, G M Janini, G M Muschik, H J Issaq
Micellar electrokinetic chromatography (MEKC) with laser-induced fluorescence (LIF) was used for the rapid and sensitive detection of hydroxyproline in serum and hydrolyzed urine that were pre-column derivatized with 9-fluorenylmethyl chloroformate (FMOC). The application of the combined o-phthalaldehyde (OPA)/FMOC derivatization in MEKC for the selective detection of secondary amino acids in biological samples is investigated.
December 22, 1993: Journal of Chromatography
I Klein, J Welink, W J van der Vijgh
The cytostatic agent Elsamitrucin is a new fermentation product active in a variety of in vivo tumor models of murine and human origin. To determine its pharmacokinetics during the clinical phase I trial, an HPLC procedure was developed and validated. Plasma samples were extracted after addition of the internal standard, i.e. the analog Chartreusin. Urine samples were injected without extraction of the samples. Because of the wide concentration range of Elsamitrucin in the plasma samples two standard curves were used: up to 100 nM and from 100-1000 nM...
December 22, 1993: Journal of Chromatography
L A Romanyshyn, J K Wichmann, N Kucharczyk, R D Sofia
An isocratic liquid chromatographic method employing one extraction step and a 150 mm x 4.6 mm I.D. Spherisorb ODS2, 3-microns HPLC column using UV-absorbance detection at 210 nm has been developed for the quantitation of felbamate and three felbamate metabolites in 0.100-ml aliquots of rat and dog plasmas. The linear quantitation range in rat plasma is 0.195-200 micrograms/ml for felbamate; 1.563-200 micrograms/ml for the p-hydroxy metabolite; 0.391-200 micrograms/ml for the 2-hydroxy metabolite; and 0.098-200 micrograms/ml for the monocarbamate metabolite...
December 22, 1993: Journal of Chromatography
L A Romanyshyn, J K Wichmann, N Kucharczyk, R D Sofia
An isocratic liquid chromatographic method for direct sample injection has been developed for the quantitation of felbamate and four metabolites in rat cerebrospinal fluid. The method uses 0.050- or 0.025-ml aliquots of cerebrospinal fluid diluted with equal volumes of internal standard. Chromatography is performed on a 150 mm x 4.6 mm I.D. Spherisorb ODS2, 3-microns HPLC column eluted with a phosphate buffer-acetonitrile-methanol (820:120:60, v/v/v) mobile phase and ultraviolet absorbance detection at 210 nm...
December 22, 1993: Journal of Chromatography
J G Dorsey, M G Khaledi
Liquid chromatography has long been used for the estimation of "hydrophobicity" of solutes of biological, environmental and agricultural interest. These measurements have taken the form of octanol-water partition coefficient estimation, or less often the more fundamental processes that the octanol-water partition coefficient is intended to model. Here we review both the chromatographic methods used for these estimations, their successes and failures, and discuss pertinent solution thermodynamics of the partitioning of small molecules between bulk phases, such as octanol and water, and between a bulk phase and an interphase, such as partitioning of solute molecules into lipid layers and biological membranes...
December 17, 1993: Journal of Chromatography
J F Wheeler, T L Beck, S J Klatte, L A Cole, J G Dorsey
We provide a somewhat historical perspective on the work that has been accomplished that supports the suggestion of phase transitions in reversed-phase liquid chromatographic bonded phases. In addition to this general review, we consider from both a practical and theoretical viewpoint the implications of such transitions in the rational design of improved reversed-phase separations. Analytical theory and molecular simulation approaches to chromatographic stationary phases and related systems are reviewed. Initial results are presented on the temperature, density and chain length dependences of stationary phase properties...
December 17, 1993: Journal of Chromatography
O V Olesen, B Poulsen
A fully automated method for determination of clozapine and desmethylclozapine in human serum using high-performance liquid chromatography was developed. On-line solid-phase extraction was performed on an exchangeable cyanopropyl cartridge. The analytes were eluted with a methanol-ammonium acetate buffer mobile phase, separated on a silica column, and measured by ultraviolet detection at 261 nm. The total time for one analysis was 13 min. Inter-day variation was < 6% and < 8% for clozapine and desmethylclozapine, respectively...
December 8, 1993: Journal of Chromatography
M Tomita, T Okuyama, S Sato, H Ishizu
We applied micellar electrokinetic capillary chromatography to simultaneous separation and determination of nitrazepam and its major metabolites, 7-aminonitrazepam and 7-acetamidonitrazepam, in spiked urine. Prior to electrophoresis, the three compounds were successfully extracted from the spiked urine with commercial disposable solid-phase cartridges. The optimum running buffer for the separation was prepared by combining 85 parts of 60 mM sodium dodecyl sulphate-6 mM phosphate-borate, adjusted to pH 8.5, with 15 parts of methanol...
November 24, 1993: Journal of Chromatography
K Matsuura, M Kuwano, H Takashina
A new method has been developed for rapid analysis and determination of pilocarpine in aqueous humour using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. The chromatography was carried out on a reversed-phase phenyl column with 0.1% acetic acid-acetonitrile (95:5, v/v). Pilocarpine and its analogues, isopilocarpine, pilocarpic acid and isopilocarpic acid, were separated. An aqueous humour sample was deproteinized with methanol. After evaporation, the residue was dissolved in the mobile phase...
November 24, 1993: Journal of Chromatography
M Breda, E Pianezzola, M S Benedetti
A sensitive and selective high-performance liquid chromatographic method for the determination of 6-methylen-androsta-1,4-diene-3,17-dione (exemestane) and its 17-dihydro metabolite in human plasma has been developed. The analytes and internal standard (Norgestrel) were extracted from plasma samples with a methylene chloride-iso-octane mixture; the organic phase was dried and the residue was reconstituted with an acetonitrile-water mixture, then analyzed by reversed-phase liquid chromatography. Quantification was achieved by ultraviolet detection of the eluate...
October 29, 1993: Journal of Chromatography
N Kiba, Y Goto, M Furusawa
A liquid chromatographic system for the determination of glucose and 1-deoxyglucose in serum using an immobilized pyranose oxidase reactor and chemiluminescence detection is described. Separation was achieved on a TSK gel SAX column (2 cm x 4 mm I.D.) with an eluent of 0.1 M sodium hydroxide solution. Serum was diluted 30-fold with 0.1 M NaOH. Sample solution (50 microliters) was injected into the system. The hydrogen peroxide produced was detected by measuring the chemiluminescence emitted on admixing with luminol and potassium hexacyanoferrate (III)...
October 22, 1993: Journal of Chromatography
P V Gogineni, P A Crooks, R B Murty
The use of liposomal formulations is rapidly gaining popularity in pharmaceutical research and development. Their preparation often involves the use of organic solvents such as tert.-butanol to dissolve lipophilic lipids. To improve the physicochemical stability of the liposomes, lyophilizing the product is one of the best available means. A gas chromatographic method for the determination of tert.-butanol residual levels in lyophilized liposomes, employing sec.-butanol as internal standard, using a flame ionization detector (FID) detector and a cross-linked dimethylpolysiloxane capillary column, was developed...
October 22, 1993: Journal of Chromatography
P Simon, T Nicot
2-Thiothiazolidine-4-carboxylic acid (TTCA) is the accepted urinary indicator of occupational exposure to carbon disulfide. An extractionless automated column-switching procedure for the determination of this compound in urine was developed. The biological fluid is directly injected into the chromatographic system after dilution. A clean-up procedure is performed in an anion-exchange pre-column, with aqueous formic acid as eluent, followed by a transfer to a cyan-amino or amino analytical column in order to carry out analysis of TTCA under isocratic elution conditions, with a mixture of acetonitrile, water and formic acid as eluent, combined with ultraviolet detection...
October 22, 1993: Journal of Chromatography
H C Shin, M Shimoda, E Kokue, Y Takahashi
Reduced folate derivatives in rat bile were examined using high-performance liquid chromatography with electrochemical detection (HPLC-ED). Three peaks of folate compounds were observed on the chromatograms. From the retention-time profiles and hydrodynamic voltammograms, and the profiles of ultraviolet (UV) absorbance spectra obtained by HPLC with photodiode array detection, these 3 peaks were identified as 10-formyltetrahydrofolate (10-HCO-H4PteGlu), tetrahydrofolate (H4PteGlu) and 5-methyltetrahydrofolate (5-CH3-H4PteGlu)...
October 22, 1993: Journal of Chromatography
D Darmaun, D D'Amore, M W Haymond
A method is described for measuring glutamine (GLN) and alpha-ketoglutarate (KG) concentration and specific activity (SA) using high-performance liquid chromatography (HPLC). Plasma GLN and KG are separated on miniature ion-exchange columns. KG is derivatized with O-phenylene diamine, the derivative is extracted in ethyl acetate, dried, and dissolved in pH 7 phosphate buffer. The isolated GLN is enzymatically converted to KG and analysed as such. Derivatized samples are stable for weeks at -20 degrees C. Samples are injected onto a reversed-phase HPLC column...
October 22, 1993: Journal of Chromatography
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